Why There May Never Be A Cure For Ebola

Medical staff working with
Medecins sans Frontieres (MSF) prepare to bring food to patients
kept in an isolation area at the MSF Ebola treatment centre in
Kailahun July 20, 2014.REUTERS/Tommy
Trenchard

Ebola has no cure, no medical treatment—and in this deadly West
Africa outbreak, doctors can only isolate victims and find those
they had come into contact with to track the virus' spread.

But it's not like researchers have been sitting around on their
hands, waiting for a solution to appear. Many pharmaceutical
companies and researchers have been testing possible cures for
years.

So what's stopping them? To begin with, antiviral therapy
is an especially challenging field compared to bacterial
diseases, because viruses have fewer targets for treatment (read:
proteins, which drugs can work with), and they evolve quickly. If
a vaccine is developed today that works, it might not make a dent
in future outbreaks. And with five known species of Ebola virus, there's plenty
of room for further viral evolution.

More important, Ebola is—and this should be obvious by now—an
incredibly dangerous virus to handle. It requires high-level
safety equipment and special facilities, deemed "biosafety level
4" or the highest level of protection, to keep labs in check.
It's costly, hard to control, and a major roadblock to progress.

"Antiviral therapy has lagged behind antibacterial therapy for
decades," Derek Gatherer, a bioinformatics researcher at
Lancaster University in the U.K. told Fox News. "There's only a handful of
places in the world where you can actually do Ebola
experimentation."

But aside from the safety issues, the two predominant obstacles
to having a widespread cure revolve around ethical and economical
questions.

As a practicing clinician, if I was given the option to
help people with a drug that isn't proven, but has been shown
to have at least some effect, it's unethical not to give it to
them.

[But] in the midst of such a huge epidemic, one could even
argue that doing a blind controlled trial would be unethical,
because if you give a placebo to some people, who will most
likely die, then you are depriving them of a drug that could
cure them, something that could save their life.

The economical side is more, well, deplorable, according
to Dr. Stephen Morse, an epidemiologist at Columbia
University's Mailman School of Public Health. "The vaccine
companies of course have to be driven by the economic
considerations," he told the Huffington Post. "It's a terrible
thing to say, but they have to be convinced that it's
economically... worthwhile to provide the vaccine."

And these two reasons have again and again driven cures away from
moving further than trial stages. Here, a review of the major
ones that are or have been pursued:

BCX4430

Description: The drug, developed by North
Carolina-based BioCryst Pharmaceuticals, has proven most adept at preventing death from the Marburg
virus, a strain that acts similarly to Ebola. It inhibits
Ebola virus reproduction by blocking its replication of its RNA
genome, a process called chain termination.

Why It's Not Available: Rob Bennet,
BioCryst's vice president of investor relations and operations,
put it this way: "Our challenge right now is that,
in the absence of human safety data, we don't see a path to dose
patients without at least some fundamental safety data. There
would be some ethical issues around that, so it's a catch-22." In
other words, human testing is too risky, despite the funding
BioCryst has ready to go. Until there's a way to safely do so,
the drug will have to wait.

Tekmira's Interfering RNA Molecule

Description: Though it doesn't have a name
yet, it follows the same idea of targeting RNA in
Ebola. Developed by British Columbia-based Tekmira
Pharmaceuticals, these molecules are placed inside lipid
nanoparticles and would fight the RNA polymerase L protein on the
Ebola virus.

Why It's Not Available: The
F.D.A. placed it on hold to investigate its
process, which would involve an "intense dosing regimen,"
according to Dr. Mark Murray, president and CEO of
Tekmira, in a statement. The drug is in phase 1 trials
and will remain there until the FDA lifts its hold.

AVI-7537

Description: This one's been in development for a long time, and got as far
as a contract with the U.S. Department of Defense in 2010 for
further testing. The AVI-7537, the sister drug of AVI-7288
targeting the Marburg virus, is specifically for Ebola viruses,
unlike the BCX4430. Like the BCX4430 and Tekmira's work, however,
it's also RNA-based, and uses phosphoramidate morpholino
oligomers to penetrate cells and resist metabolism
(Ebola metabolizes and replicates quickly, which causes
hemorrhaging and eventual death).

Why It's Not Available: The D.O.D.
discontinued the Ebola part of the contract with Sarepta in
October 2012 and never reactivated it. According to a report in
the Financial Times, budget cuts caused the scrapping of the
program for Ebola, though research continues on the AVI-7288 for
the Marburg virus.

Favipiravir

Description: In a study
titled Successful Treatment of Advanced Ebola Virus
Infection with T-705 (Favipiravir) in a Small Animal Model,
researchers tested this drug on small animals, and found that it prevented Ebola
infection in all the animals tested. It's also
more a broad anti-viral drug, as it uses a compound
that works against viral enzymes in general, tending to flu
symptoms and blocking the virus' replication. Whether it's
strong enough to stop Ebola in humans remains to be seen.

Why It's Not Available: Similar to BCX4430,
it's only been used on small animals, and is nowhere near testing
on humans.

None of these drugs are close to widespread dissemination.
Instead, the Americans infected in the outbreak have received
experimental treatments. One received a dose of a serum, though little information
is available on how it works. The other has been given a unit of blood from a 14-year-old
patient who survived Ebola. The idea behind the blood, of
course, is that if its plasma's antibodies
managed to fend of the virus, it could do so in the infected
doctor's body.

Yet, even with the the escalating emergency in West Africa, it's
important to remember the outbreak has a slim chance of spreading
past the region. Ebola requires contact with bodily fluids to
spread, and the outbreak has been mostly attributed to
less-than-ideal conditions.

"Ebola outbreaks [have] become so widespread because of the
hospital conditions and poor resources," Barbara Knust, Ebola
expert at C.D.C., told the Financial Times. "Health workers
might not even have access to gloves and family members of
infected people might not have running water to wash their
hands."

Plus, Peter Piot, who co-discovered Ebola in 1976, told
Agence France-Presse he would not be afraid to be around
an infected person. "I wouldn't be worried to sit next to someone
with Ebola virus on the Tube as long as they don't vomit on you
or anything," he said. "This is an infection that requires very
close contact."

In the meantime, doctors must continue to isolate patients in the
outbreak, and pharmaceutical companies must determine whether a
cure or vaccine is worth pursuing. Is more than 1,300 cases reported in West Africa enough?